This invention relates to a friction clutch adapted to automotive vehicle, and more particularly to such clutch having driving and driven members to be frictionally connected with or disconnected from each other by being axially displaced relative to each other for frictional engagement, damper means for cushioning torque applied from the driving member to the driven member with a torsion developed between the driving and driven members when the clutch is being engaged, and stopper means to firmly couple the driving and driven members in order to enable the torque to be applied to the fullest extent to the driven member causing the damper means stand inactive.
In the type of clutch, the damper means must provide better cushioning of the torque applied to the driven member in order to start or accelerate the automotive vehicle smoothly with rapidity. With light vehicles or slow starting or acceleration of vehicles, the problem is relatively simple, but the difficulties multiply as weight and speed are increased.
None of the conventional clutches of such type, however have proven to be entirely sufficient with the class of service above mentioned i.e., when the clutch is being engaged, the damper means is apt to be early deformed or to early yield to its fullest extent by the torque even though the torque is not yet increased to one large enough to meet the requirement for driving the vehicle. This drawback is considered to be a defect in that, the stopper means and the hub member come to impulsively collide with each other almost every time the clutch is being engaged and repeating the collisions results in ruin of them. The repeated collisions may be attributed to the elastic characteristics of the damper means which does not strictly meet complex requirement of the cushioning of the torque applied to the driven member. In short, the damper means of rubber material and other similar elastic material tends to lack rigidity at a later stage during the cushioning operation when the clutch is being engaged.